JP2005091359A - Device for electrically connecting bga package with signal source, and method for making such connection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device which can produce easily and has property excellent in a cost performance. <P>SOLUTION: A contact mechanism is a part of a flexible PCB 3 having a Cu conductor resistance path 9 distributed between flexible plastic layers 7, 8. A columnar or cylindrical contact member 5 penetrates and extends through the flexible PCB 3. The contact is connected electrically with the Cu conductor resistance path 9, and also the contact projects on either face from one side of the plastic layers 7, 8. The contact mechanism can be realized by the above constitution. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a contact receptacle having a guide member for a BGA package, and terminals of the BGA package disposed in the contact socket and used for a burn-in test and a functional test. The present invention relates to an apparatus for electrically connecting a BGA package and a signal source using a contact mechanism for electrically contact-connecting a signal source.

  The contact socket for the functional test of the FPBGA package, which is usually used for the functional test of the FPBGA package, is a spring pin (pogo pins) or a micro spring contact part (electric contact-electric connection). micro-spring contacts). The spring pins or microspring contact portions are used for connection to the contact terminals and take the form of solder ball contact arrays of the FPBGA package. In this case, the contact portion is accurately arranged at a grid pitch like a solder ball in a microsphere contact arrangement.

  However, these contacts do not meet future requirements for test sockets. Consider unresolved issues such as energy transfer with loss due to existing discontinuities and contamination of the test system due to very fine abrasion on all sliding parts in the test system There is a need to.

  For example, in the case of a commonly used spring pin having a length of about 5 mm, the limiting frequency is 1 GHz. This is due to the dynamic internal resistances of the contact system.

  In addition, the test sockets are subject to high thermal loads due to the ever-increasing miniaturization of integrated circuits and the associated reduction in heat dissipation. As a result, both the contact portion and the solder ball are subjected to a serious heat load, and rapidly deteriorate.

  Furthermore, the continual reduction of the connection pitch results in a non-linear rise during signal crosstalk, which is unavoidable with known technical solutions such as spring pins.

  For the above reasons, there is a need to develop a cost-effective test socket that is extremely mechanically stable, less susceptible to heat, and solves the interference problem when the connection pitch is short. In this case, the contact portion must have excellent self-cleaning capacities and be able to securely penetrate the substrate disposed on the contact sphere.

  A further development objective is to achieve more than 250,000 contact connections per contact socket under manufacturing conditions. In addition, because a high frequency test signal is required, a specific voltage is applied from the energy source to the DUT (device under test), ie lossless energy to the BGA package being tested. Therefore, all signal paths including the printed circuit board need to be optimized, and it is required that the test socket can be repaired and replaced without problems.

  Therefore, the present invention provides a contact socket having a guide member for a BGA package, and a contact that is disposed in the contact socket and that electrically contacts and connects terminals of a BGA package (DUT) for an electrical test and a function test. A device for electrically connecting a BGA package and a signal source using a mechanism, which can be easily manufactured and cost effective, and a method for manufacturing a contact mechanism It is an object.

  The object of the present invention is that in a device of the kind mentioned in the opening part, the contact mechanism has a flexible PCB (printing) with Cu conductor resistance tracks arranged between flexible plastic layers. Part of a printed circuit board), a column- or sleeve-shaped contact extending through the PCB, the contact being electrically This is achieved by the fact that it is connected to a Cu conductor resistance path and protrudes upwards on one side from one of the plastic layers.

  The novel point of this contact system is realized by applying a defined pressure to the chip, ie the contact between its bonding pads and the contact part. Is a point.

  As a first refinement of the present invention, a flexible PCB (printed circuit board) is placed in the contact socket on the elastic structure. Therefore, the spring excursion normally required to maintain the contact force in the case of conventional spring pins is thus more elastic, depending on the elasticity of the flexible substrate and, if appropriate, more elastic. This is realized by an additional member.

  Elastomer inserts, potting foams, thermoplastic elastomers, or rubber or rubber-like members may also be provided as contact-force-maintaining elements Good.

  In the development of the present invention, the contact force maintaining member is disposed below the PCB by being arranged from the back side, inserted from the back side, bonded, hot sealed, or covered with rubber. Will be placed. In this case, the contact force maintaining unit may have a composite adhesion with the PCB.

  A further improvement of the invention is characterized in that the PCB is removably connected to the contact socket.

  Finally, the contact socket is a member intended to dissipate heat due to power loss. Therefore, the chip can be prevented from being heated unnecessarily.

  Furthermore, the object of the present invention is achieved by the fact that the contact socket is a member intended for uniform heat distribution.

  Furthermore, the contact socket may be provided with other components such as backup capacitors, and the supply line of the contact socket is formed as a flexible substrate.

  Another improvement of the present invention is that the contact mechanism is detachably connected to the contact socket.

  Also, to improve electrical contact, the contacts have crowns that are pressed into the contacts by a force-locking and positively locking manner. Is provided.

  A further object of the present invention is to introduce microvias at the pitch of the BGA into a flexible PCB having a Cu conductor resistance path disposed between the flexible plastic layers, after which the microvias are electrically conductive. A contact member is manufactured by filling a conductive material and covering at least the wall of the microvia, and one of the flexible plastic layers of the flexible PCB is thinned by etching, and the conductive filling is performed. This is achieved by a method characterized by partially projecting material from the surface.

  The flexible plastic layer may be thinned by plasma etching or other appropriate selective etching method.

  Furthermore, the improvement of the present invention is that microvias are introduced into the flexible PCB using photolithography together with plasma etching.

  Microvias can also be mechanically introduced into the flexible PCB.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  FIG. 1 is a view showing an apparatus for electrically connecting a flexible PCB and a contact portion in a contact socket in order to contact-connect a BGA package. FIG. 2 shows a variant of the device according to FIG. 1 with an added contact crown.

  The present invention is to connect the terminal 1 of the FPBGA package 2 and a signal source (not shown) detachably with a flexible PCB 3 used particularly in the field of energization test and function test with little electrical loss. A configuration of a new contact system will be described.

  The contact system includes a contact socket 4. The contact socket 4 receives the package 2 to be contact-connected by a reliable fixing method. The contact connection between the chip terminal 1 and the corresponding contact member 5 in the flexible PCB 3 is performed by applying a prescribed pressure to the package 2. Further, in order to simplify the insertion of the package 2 to be contact-connected, the contact socket is provided with a guide level 6.

  The flexible PCB 3 includes two polyimide films 7 and 8, and a Cu conductive resistance path 9 is disposed between them as one or a plurality of surfaces (layers).

  The corresponding contact member 5 on the flexible PCB 3 has a columnar shape, a sleeve shape, or a similar shape. The contact member 5 is partly formed by plasma etching, and a part thereof is the flexible PCB 3 (polymer substrate). Not covered. As a result, a depression 10 is formed in the region of the contact member 5.

  In order to form such a columnar or cylindrical contact member 5, holes are formed in the polymer substrate so as to be connected to the chip 2 or the FPBGA package accurately at the contact point by, for example, stamping or plasma etching. (Microvia) is introduced and the hole is filled with a conductive material. Next, after removing the hole etching mask necessary for plasma etching, the flexible substrate material can be partially removed by an even more selective plasma etching operation. As a result, the depression 10 is generated in the polymer substrate, and only the cylindrical contact mechanism 5 remains in a pin shape like a cylinder. The thinning may be performed by other appropriate selective etching methods.

  In this regard, the present invention also encompasses all techniques for forming the crown 11 at the end of the contact mechanism 5 (pin).

  Furthermore, pressing techniques can be considered as another solution for realizing a corresponding contact mechanism in a flexible substrate. In this case, the contact crown portion 11 such as a cylinder is introduced into the socket having the flexible substrate by a forcible and reliable fixing method (FIG. 2).

  In addition, the contact system configuration is characterized by the fact that the spring displacement of the conventional spring pin is usually used to maintain the contact force, in this case due to the elasticity of the flexible substrate (flexible PCB 3). This is realized by the other elastic addition member 12 disposed below the flexible PCB 3.

  Such a combination allows the flexible substrate to be connected to other elastic addition members 12, ie contact forces (eg, elastomer inserts, potting compositions or potting foaming agents, thermoplastic elastomers, and rubbers). The maintenance member and the member are characterized in that they are completely or partially synthetically adhered by, for example, arranging from the back side, inserting from the back side, bonding, hot sealing, or covering with rubber. is there.

  Furthermore, the configuration of the contact system is characterized in that the configuration of the contact system or a part of the contact system further performs other additional functions such as power loss or uniform heat distribution in addition to the generation of the contact portion. It is. Also, the integration of other components (for example, a backup capacitor) will be described.

  In order to make the internal resistance or the contact resistance as small as possible, the supply line of the contact system may be similarly realized using a flexible substrate (flexible PCB 3). Also, the contact socket 4 with the contact connection system is arranged in a carrying device so that it can be exchanged.

  In the present invention, the contact force maintaining member may be composed of an elastic member such as rubber.

  Moreover, in this invention, the said contact maintenance member is arrange | positioned from the back side of PCB3, or this contact force maintenance member is arrange | positioned under PCB3 by being inserted from the back side of PCB3.

It is a figure which shows the apparatus which electrically connects a flexible PCB and a contact part in a contact socket, in order to contact-connect a BGA package. FIG. 2 shows a variant of the device according to FIG. 1 with an added contact crown.

Explanation of symbols

1 Chip terminal 2 FPBGA package 3 Flexible PCB
DESCRIPTION OF SYMBOLS 4 Contact socket 5 Contact member 6 Guide surface 7 Polyimide film 8 Polyimide film 9 Cu conductor resistance path 10 Depression 11 Crown part 12 Elasticity addition member

Claims (21)

A BGA using a contact socket having a guide member for a BGA package and a contact mechanism arranged in the contact socket and electrically contacting and connecting terminals of a BGA package (DUT) for current test and function test In an apparatus for electrically connecting a package and a signal source,
The contact mechanism is part of a flexible PCB (3) having a Cu conductor resistance path (9) disposed between the flexible plastic layers (7, 8);
Furthermore, a cylindrical or cylindrical contact member (5) is provided,
This contact member is
Extending through the flexible PCB (3), electrically connected to the Cu conductor resistance path (9), and
A device characterized in that it protrudes on either side from one of the plastic layers (7, 8).   The device according to claim 1, characterized in that the flexible PCB (3) is arranged in the contact socket (4) on the elastically added member (12).   The apparatus according to claim 1 or 2, further comprising a contact force maintaining member below the flexible PCB (3).   The apparatus according to claim 3, wherein an elastomer insert is provided as the contact force maintaining member.   4. The apparatus according to claim 3, wherein a potting component or a potting foaming agent is provided as the contact force maintaining member.   The apparatus according to claim 3, wherein a thermoplastic elastomer is provided as the contact force maintaining member.   The apparatus according to claim 3, wherein a rubber or a rubber-like member is provided as the contact force maintaining member.   The contact force maintaining member is disposed below the PCB by being arranged from the back side, inserted from the back side, adhered, hot sealed, or covered with rubber, or the like. Item 8. The device according to any one of Items 3 to 7.   The apparatus according to any one of claims 3 to 8, wherein the contact force maintaining member has a synthetic adhesive force with respect to the flexible PCB (3).   10. Device according to any one of the preceding claims, characterized in that the PCB (3) is detachably connected to the contact socket (4).   The device according to claim 1, wherein the contact socket is a member intended to dissipate heat due to power loss.   12. The device according to claim 1, wherein the contact socket (4) is a member intended for uniform heat distribution.   Device according to any one of the preceding claims, characterized in that another member, such as a backup capacitor, is provided in the contact socket (4).   14. A device according to any one of the preceding claims, characterized in that the supply line of the contact socket (4) is formed as a flexible substrate.   15. Device according to any one of the preceding claims, characterized in that the contact mechanism is detachably connected to the contact socket (4).   Device according to any one of the preceding claims, characterized in that the contact member (4) comprises a crown (11).   17. Device according to claim 16, characterized in that the crown (11) is pushed into the contact member (4) by a forced and secure fastening method. In the manufacturing method of the contact mechanism according to claim 1 to 17,
Introducing microvias at the pitch of the BGA into a flexible PCB (3) having a Cu conductor resistance path (9) disposed between the flexible plastic layers (7, 8);
Subsequently, the micro via is filled with a conductive material, and at least the wall of the micro via is coated to produce a contact member (5),
One of the flexible plastic layers of the flexible PCB (3) is thinned by etching, and the conductive filling material partially protrudes from the surface so that the contact member (5) is formed. Method.   The method according to claim 18, wherein the thinning is performed by plasma etching or selective etching.   20. The method according to claim 18 or 19, wherein the microvia is introduced into the PCB by photolithography.   20. A method according to claim 18 or 19, wherein the microvia is mechanically introduced.

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